Field of the Invention
This invention relates generally to an integrated antenna assembly and full display mirror (FDM) camera module and, more particularly, to an integrated vehicle roof mounted antenna assembly and FDM camera module, where the camera module is positioned so that it is pointing upward and does not interfere with the radiation pattern of any of the antenna elements in the assembly, and where the camera module includes an optical element that redirects the image plane of the module behind the vehicle.
Discussion of the Related Art
Conventional vehicles include an internal rear-view mirror mounted to a center location of the vehicle windshield. When a driver of the vehicle looks into the rear-view mirror to see objects behind the vehicle, various things inside the vehicle, such as seat headrests, passengers, etc., block some of the view provided by the mirror. It has been proposed in the art to replace the traditional rear-view mirror of a vehicle with a full display mirror (FDM) that is coupled to a rearward facing camera on the vehicle that provides an image displayed on the mirror. The displayed image provided by the camera typically has a wider field-of-view than the mirror, and is not obstructed by anything in the vehicle. The FDM can be put in a camera mode where the image from the camera is displayed on the mirror or in a reflective mode where the traditional rear-view from the mirror is provided. Thus, if the camera is blocked by dirt, snow, etc., or malfunctions, the vehicle operator can switch to the reflective mode for viewing objects behind the vehicle.
Modern vehicles typically include a back-up camera generally mounted proximate the back license plate on the vehicle that provides images to a display on the vehicle when the vehicle is in reverse. However, a number of issues, such as safety concerns, government regulations, etc., do not allow the traditional back-up camera on a vehicle to be used as an FDM camera. Further, the field-of-view of the back-up camera is generally significantly more limited than what is necessary for an FDM camera. Thus, a separate camera is necessary for an FDM in addition to the back-up camera. It has been proposed in the art to position the FDM camera adjacent to or proximate to the back-up camera. However, this area of a vehicle is typically susceptible to dirt, mud, snow, ice, etc., which obscures the lens of the FDM camera, and often prevents it from being usable.
Modern vehicles employ various and many types of antennas to receive and/or transmit signals for different communications systems, such as terrestrial radio (AM/FM), cellular telephone, satellite radio, dedicated short range communications (DSRC), GPS, etc. Often the antennas used for these systems are integrated in a common antenna module that is mounted to a roof of the vehicle so as to provide maximum reception and transmission capabilities.
It has been proposed in the art to integrate an FDM camera in a vehicle roof mounted antenna module so that the camera is pointing rearward of the vehicle proximate the vehicle roof line, which is similar to the normal view of the rear-view mirror. This location for an FDM camera benefits from the aerodynamic configuration of the antenna module in that wind direction and pressure differentials prevent significant dirt accumulation at the backend of the antenna module, and thus does not obscure the camera lens.
A typical FDM camera will include relatively large metal components to which the camera circuit board, power supply and other camera structures are mounted. Because the FDM camera needs to be pointing rearward of the vehicle, these metal structures are typically configured in a vertical direction, perpendicular to the plane of the vehicle roof. In this configuration, the metal structures in the camera often times interfere with the radiation pattern of all or most of the antenna elements in the antenna module, thus impacting antenna performance. Particularly, the antenna elements are unable to operate in a complete omni-directional manner to receive and transmit signals from all directions around the vehicle.